Catherine Duchess Of Cambridge's child, if it's a girl, will need legal help to ascend to the British throne. / Chris Jackson, Getty Images

by Maria Puente, USA TODAY

by Maria Puente, USA TODAY

In all the hoopla over the "historic" new royal baby on the way, some people have forgotten an inconvenient truth: Laws that must be passed to give equal rights to a girl child have not yet been passed.

Oops.

Not to worry, promise British constitutional experts as well as leading British politicians. "I don't see a problem - this baby will impel them to get it done in time," predicts Elisabeth Cawthon, a historian of British law at the University of Texas.

When the palace announced Monday that Prince William and his wife Catherine, Duchess of Cambridge are expecting their first baby, it was especially newsworthy: If this baby is a girl, she will be third in line to the throne even if she has brothers born later.

That's because the U.K. and the 15 other Commonwealth realms that recognize the British monarch as head of state have agreed to throw out ancient laws that say boys always come first in the succession no matter their birth order.

But so far, they haven't even introduced the necessary legislation, let alone voted. By Tuesday, cooler heads among British constitutional experts prevailed, pointing out that if the Cambridge baby is a girl born before all the necessary laws are passed, it could be awkward.

As royal historian Robert Lacey has been telling reporters, "Law only becomes law when the law is made - and the law has not been made."

But it will, promises deputy prime minister Nick Clegg. He says a new law on female succession would be introduced in Parliament as soon as possible so that the change can happen before Duchess Kate's baby is born.

"Notwithstanding a few parliamentary turns of the wheel, this is now going to happen," Clegg told reporters, according to the Associated Press. He added that "the old-fashioned rules ... have been swept aside."

Luckily, says Cawthon, all it takes is a majority vote in Parliament to change the unwritten British constitution, unlike the deliberately time-consuming process and two-thirds vote of the states required to amend the U.S. Constitution. Same for the Commonwealth realms such as Canada, Australia and New Zealand.

Moreover, she says, virtually no one is opposed to changing the gender rules. In part, that's because the change is seen as a tribute to two highly successful, admired and popular queens in the past 150 years, Queen Victoria and her great-great grandchild, Queen Elizabeth II.

Also, the status quo is largely seen as embarrassing and indefensible. "The current state of affairs is not consonant with European human rights - and this is a bad one to look bad on," says Cawthon. "This is something the British increasingly find ridiculous."

Other areas of possible legislative change, such as the rules against heirs to the throne marrying Roman Catholics, might be more difficult to achieve quickly and thus might be put off.

But not the gender rules. "People regard this as stepping into the 21st - no, the 20th century," Cawthon joked.